The maximum pulse rating of many standard current transformers (or monitors) is limited by the voltage rating of the output connector. Typically, this is in the neighborhood of 500 volts. However, most oscilloscopes can only handle an output signal from a current transformer having a voltage below 40 volts.
Current transformer attenuators have been used in the past to provide oscilloscopes with voltages that they can handle. However, these attenuators do not provide the total combination of (a) adequate input to output voltage reduction, (b) matched impedance at the input and output terminals of the attenuator, (c) enough peak power capacity for the output signal of standard current transformers, and (d) a bandwidth commensurate with the current transformers to which they are coupled.